Method and apparatus for forming a hole

ABSTRACT

An apparatus for drilling out a plug of material, the apparatus comprising: a base plate having a top surface, a bottom surface, and a central longitudinal axis; a circumferentially-extending side wall extending distally from the top surface of the base plate, the circumferentially-extending side wall terminating in a circular distal end surface; a drill bit centered on the central longitudinal axis of the base plate and extending distally therefrom, the drill bit comprising a distal portion, a proximal portion and an intermediate portion extending between the distal portion and the proximal portion; wherein the intermediate portion of the drill bit comprises a first laterally-extending flat comprising a cutting edge disposed a first distance away from the central longitudinal axis towards the circumferentially-extending side wall and a second laterally-extending flat extending a second distance away from the central longitudinal axis towards the circumferentially-extending side wall, and further wherein the first distance is greater than the second distance.

FIELD OF THE INVENTION

This invention relates to drilling apparatus in general, and moreparticularly to novel methods and drilling apparatus for forming a holein a material, and for removing the drilled-out material from the holethat is drilled out, and from the drilling apparatus.

BACKGROUND OF THE INVENTION

During construction (e.g., of buildings and other structures), it iscommon to drill holes in building materials in order to accommodatevarious systems, e.g., plumbing, electrical conduits, HVAC components,etc. By way of example but not limitation, where such systems aredisposed behind the finished drywall of a residential or commercialstructure, it is common to drill relatively large diameter holes in thestuds behind the drywall (e.g., to permit passing piping or conduitthrough the studs), to drill relatively large diameter holes in plywood(e.g., to permit passing piping or conduit through an exterior wall andhence, through the exterior plywood sheathing), to drill relativelylarge diameter holes in ceilings (e.g., to accommodate automatic firesprinklers, lighting, etc.), and in various other contexts.

Where the holes to be drilled are of relatively small diameter (e.g.,⅛″), it is common to use a traditional “cork-screw” style drill bit. Inuse, such a “cork-screw” style drill bit operates by cutting into amaterial (e.g., wood) using a quickly rotating pointed end, and thenpassing debris from the hole drilled into the material by the pointedend along a cork-screw-type recess disposed along the side of the drillbit such that the debris drilled out of the material exits the drillhole. When the drill bit is removed from the drill hole, a hole havingthe same diameter as the drill bit is left in the material, throughwhich something may thereafter be passed (e.g., a wire, a fastener,etc.).

However, where it is desirable to drill large diameter holes (e.g., a2.5″ diameter hole), such as may be necessary, for example, toaccommodate plumbing conduit, etc., it is common to use a “barrel-style”drill apparatus such as the HOLE DOZER™ barrel-style drill apparatusmanufactured by Milwaukee Electric Tool Corporation of Brookfield, WI.

With such a prior art “barrel-style” drill apparatus, a hole is drilledin a material by centering the drill apparatus on the centerpoint of acircle inscribing the hole that is to be drilled, and then rotating theouter wall of the “barrel-style” drill apparatus (e.g., using a powerdrill) so as to cut a circumferentially-extending (i.e., circular) slotin the material along the perimeter of the circle inscribing the holethat is to be drilled. Once the rotating outer wall of such a“barrel-style” drill apparatus has been advanced sufficiently farthrough the material in which the hole is being made (e.g., so as toextend through the material to the opposite side of the material), thedrill apparatus is withdrawn, leaving a hole in the material having thesame diameter as the diameter of the outer wall of the “barrel-style”drill apparatus, and leaving a “plug” of the material which has beendrilled out disposed inside the recess defined by the outer wall of the“barrel-style” drill bit.

More particularly, and looking now at FIGS. 1 and 2 , there is shown anexemplary prior art “barrel-style” drill apparatus 5 which generallycomprises a base plate 10, a circumferentially-extending side wallextending upwardly from base plate 10 so as to define a recess 20, and acentering drill bit 25 centered on base plate 10 (FIG. 2 ) and extendingupwardly therefrom such that drill bit 20 extends slightly beyond thecutting edge of circumferential side wall 15 (e.g., in order to assistin drilling a “starter hole” with drill bit 20 so as to assist incentering the drilling apparatus on the material which is to bedrilled). Side wall 15 terminates in a circumferentially-extendingcutting edge 30 which comprises a plurality of spaced teeth 35 disposedalong cutting edge 30 (i.e., teeth configured for cutting thecircumferentially-extending slot in the material which is to be drilledout).

In use, centering drill bit 25 of “barrel-style” drill apparatus 5 isaligned with a centerpoint of a circle inscribing the hole which is tobe drilled out on the surface of a material. Centering drill bit 25 isthen rotated (e.g., using a power drill) so as to form a “starter hole”in the center of the material which is to be drilled out. Typically,centering drill bit 25 is fixed to, or formed integral with, base plate10, such that rotation of centering drill bit 25 causes simultaneousrotation of side wall 15. However, since centering drill bit 25typically extends slightly beyond circumferentially-extending cuttingedge 30, centering drill bit 25 typically contacts the material to bedrilled before teeth 35 of cutting edge 30. Centering drill bit 25 (andside wall is then rotated further, advancing centering drill bit 25further into the material until teeth 35 of cutting edge 30 of side wall15 contact the material and begin forming a circumferentially-extendingslot in the material which is to be drilled out. As “barrel-style” drillapparatus 5 is advanced further into the material, thecircumferentially-extending slot extends further into the material. Oncethe “barrel-style” drill apparatus 5 has been advanced through thematerial which is being drilled (i.e., to the opposite side of thematerial) such that the circumferentially-extending slot extends all theway through the material which is being drilled out, “barrel-style”drill apparatus 5 is withdrawn from the hole that has been drilled,leaving a “plug” P of material (see FIG. 3 ) disposed in recess 20 of“barrel-style” drill apparatus 5 (and leaving a drilled out hole havingthe same diameter as the diameter of the circle inscribed by side wall15 in the material).

While the “barrel-style” drill apparatus 5 discussed above is effectivefor drilling a hole having a desired diameter in a material, it has beenfound that it is often difficult to remove the plug P of material whichremains in recess 20 of “barrel-style” drill apparatus 5 after thematerial has been drilled out. This problem is particularly acute wherethe material being drilled expands during drilling and binds insiderecess 20. By way of example but not limitation, pressure-treated wood(which is chemically-treated and therefore comprises some moisture) willexpand due to the heat that results from friction during drilling, withthe result that the plug P that remains inside recess 20 after drillingis completed is often difficult (and time-intensive and/orlabor-intensive) to remove from recess 20 of “barrel-style” drillapparatus 5. Prior art “barrel-style” drill apparatus typically addressthis problem by providing a plurality of windows 40 (FIG. 1 ) formed inside wall 15 so as to permit an end user to insert a lever (e.g., ascrewdriver) through a given window 40 (and hence, through side wall15), which can then be used to pry the plug P lose from recess 20.However, even where such windows 40 are provided, it is still oftenlabor-intensive and/or time-consuming to remove plug P from recess 20.This can be a particularly acute problem where plug P binds to side wall15 due to expansion of the drilled material (see above), and/or where alarge number of such holes are to be drilled.

Thus there is a need for a new and improved apparatus and method fordrilling large-diameter holes in a material which facilitates quick andeasy removal of the plug of material remaining in the drilling apparatusafter the hole has been drilled out of the material.

SUMMARY OF THE INVENTION

The present invention provides a new and improved apparatus and methodfor drilling large-diameter holes in material which facilitates quickand easy removal of the plug of material remaining in the drillingapparatus after the hole has been drilled out of the material.

In one preferred form of the invention, there is provided an apparatusfor drilling out a plug of material, said apparatus comprising:

-   -   a base plate having a top surface, a bottom surface, and a        central longitudinal axis;    -   a circumferentially-extending side wall extending distally from        said top surface of said base plate, said        circumferentially-extending side wall terminating in a circular        distal end surface;    -   a drill bit centered on said central longitudinal axis of said        base plate and extending distally therefrom, said drill bit        comprising a distal portion, a proximal portion and an        intermediate portion extending between said distal portion and        said proximal portion;    -   wherein said intermediate portion of said drill bit comprises a        first laterally-extending flat comprising a cutting edge        disposed a first distance away from said central longitudinal        axis towards said circumferentially-extending side wall and a        second laterally-extending flat extending a second distance away        from said central longitudinal axis towards said        circumferentially-extending side wall, and further wherein said        first distance is greater than said second distance.

In another preferred form of the invention, there is provided anapparatus for drilling out a plug of material, said apparatuscomprising:

-   -   a base plate having a top surface, a bottom surface, and a        central longitudinal axis;    -   a circumferentially-extending side wall extending distally from        said top surface of said base plate, said        circumferentially-extending side wall comprising an inner        surface defining a circular recess enclosed by said        circumferentially-extending side wall, an outer surface and a        circular distal end surface;    -   a cutting wedge mounted to said inner surface of said        circumferentially-extending side wall and extending laterally        inwardly in the direction of said longitudinal axis.

In another preferred form of the invention, there is provided anapparatus for drilling out a plug of material, said apparatuscomprising:

-   -   a base plate having a top surface, a bottom surface, and a        central longitudinal axis;    -   a circumferentially-extending side wall extending distally from        said top surface of said base plate, said        circumferentially-extending side wall comprising an inner        surface defining a circular recess enclosed by said        circumferentially-extending side wall, an outer surface and a        circular distal end surface;    -   a drill bit centered on said central longitudinal axis of said        base plate and extending distally therefrom, said drill bit        comprising:        -   a distal portion;        -   a proximal portion; and        -   an intermediate portion extending between said distal            portion and said proximal portion;        -   wherein said intermediate portion of said drill bit            comprises a first laterally-extending flat comprising a            cutting edge disposed a first distance away from said            central longitudinal axis towards said            circumferentially-extending side wall and a second            laterally-extending flat extending a second distance away            from said central longitudinal axis towards said            circumferentially-extending side wall, and further wherein            said first distance is greater than said second distance;            and    -   a cutting wedge mounted to said inner surface of said        circumferentially-extending side wall and extending laterally        inwardly in the direction of said longitudinal axis.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention will bemore fully disclosed or rendered obvious by the following detaileddescription of the preferred embodiments of the invention, which is tobe considered together with the accompanying drawings wherein likenumbers refer to like parts, and further wherein:

FIGS. 1 and 2 are schematic views of a prior art “barrel-style” drillingapparatus;

FIG. 3 is a schematic view showing a plug of drilled-out material boundin the recess of a prior art “barrel-style” drilling apparatus;

FIG. 4 is a schematic view of a novel “barrel-style” drilling apparatusformed in accordance with the present invention;

FIGS. 5-10 are schematic views showing further aspects of the novel“barrel-style” drilling apparatus of FIG. 4 ;

FIG. 11 is a schematic view showing a plug of drilled material in therecess of the “barrel-style” drilling apparatus of FIG. 4 after drillinghas been completed;

FIG. 12 is a schematic view showing further aspects of the novel“barrel-style” drilling apparatus of the present invention; and

FIG. 13 is a schematic view showing another novel “barrel-style”drilling apparatus formed in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a new and improved apparatus and methodfor drilling large-diameter holes in a material which facilitates quickand easy removal of the plug of material remaining in the drillingapparatus after the hole has been drilled out of the material.

For purposes of clarity, the terms “proximal” and “distal” will be usedherein with reference to a handheld drill to which the drillingapparatus is typically attached and with reference to the material whichis to be drilled out using the drilling apparatus. Accordingly, the term“proximal” will refer to the direction towards the handheld drill towhich the drilling apparatus is attached, and the term “distal” willrefer to the direction towards the material which is to be drilled bythe drilling apparatus (i.e., the direction away from the end of thehandheld drill to which the drilling apparatus is attached).

Looking now at FIG. 4 , there is shown a novel drilling apparatus 105formed in accordance with the present invention. Drilling apparatus 105generally comprises a circular base plate 110 having a proximally-facingbottom surface 115 (FIG. 7 ) and a distally-facing top surface 120, acircumferentially-extending side wall 125 extending distally from topsurface 120 of base plate 110, and a centrally-mounted drill bit 130extending distally relative to top surface 120.

Drill bit 130 is preferably releasably mounted within an opening 135formed in the center of base plate 110, such that drill bit 130 may beselectively removed and replaced (e.g., to replace due to wear, tochange for different-sized drill bits depending on desired use, etc.),and/or rotationally adjusted relative to top surface 120 of base plate110. Drill bit 130 is preferably mounted to base plate 110 such thatrotation of drill bit 130 (e.g., via an electric drill/motor mounted tothe proximal end of drill bit 130, not shown) causes simultaneousrotation of base plate 110, and hence rotation ofcircumferentially-extending side wall 125. In one preferred form of theinvention, drill bit 130 is mounted to base plate 110 via a drill bitmount 140 (FIG. 5 ) comprising one or more mounting tabs 145 sized to bereceived in counterpart openings 150 formed in base plate 110. In apreferred form of the invention, drill bit mount 140 comprises a pair ofdiametrically-opposed distally-extending tabs 145, and base plate 110comprises a plurality of diametrically-opposed openings 150 forreceiving tabs 145 when drill bit 130 is mounted to base plate 110,whereby to permit the end user to selectively adjust the rotationaldisposition of drill bit 130 relative to base plate 110 (and hencerelative to circumferentially-extending side wall 125), as willhereinafter be discussed in further detail.

Looking now at FIG. 5 , drill bit 130 generally comprises a shaft 155having a proximal end portion 160 mounted to (or formed integral with)drill bit mount 140, a distal end portion 165, and an intermediateportion 170 extending between proximal end portion 160 and distal endportion 165. Proximal end portion 160 and distal end portion 165 arecentered about a longitudinal axis 175 which is, in turn, centered onthe center of base plate 110 (i.e., when drill bit 130 is mounted tobase plate 110). Distal end portion 165 is preferably tapered to adistal point 180 configured to engage a material that is to be drilled,and distal end portion 165 preferably also comprises a “cork-screw” likerecess 185 extending around distal end portion 165, whereby tofacilitate debris removal from a “starter hole” formed in the materialwhich is to be drilled as the drill bit 130 is advanced distally, aswill hereinafter be discussed in further detail. In a preferred form ofthe present invention, tapered point 180 of distal end portion 165 ofdrill bit 130 extends distally beyond the distal-most surface ofcircumferentially-extending side wall 125, whereby to facilitatedrilling of a “starter hole” to stabilize drilling apparatus 105relative to the material to be drilled-out, as will hereinafter bediscussed in further detail.

Still looking at FIG. 5 , intermediate portion 170 of drill bit 130comprises at least one flat 190 which extends laterally relative tolongitudinal axis 175 and terminates in a lateral cutting edge 195. Itwill be appreciated that flat 190 of intermediate portion 170 isdisposed laterally asymmetrically relative to longitudinal axis 175,such that lateral cutting edge 195 is laterally offset from longitudinalaxis 175 to a greater lateral extent than the edge of flat 190diametrically-opposed to lateral cutting edge 195. Stated another way,lateral cutting edge 195 extends further laterally away fromlongitudinal axis 175 than the diametrically-opposed other edge of flat190, which is disposed laterally closer to longitudinal axis 175. Ifdesired, lateral cutting edge 195 of drill bit 130 may comprise asharpened edge in order to facilitate cutting into the material which isto be drilled, as will hereinafter be discussed in further detail. In apreferred form of the present invention, flat 190 comprises a curved(e.g., twisted) geometry along it's length, whereby to enhance cuttinginto the material which is to be drilled. It will also be appreciatedthat when drill bit 130 is mounted to base plate 110 of drillingapparatus 105, distal end portion 165 and a portion of intermediateportion 170 preferably extend distally beyond the distal end ofcircumferentially-extending side wall 125 (see FIG. 7 ), as willhereinafter be discussed in further detail.

Looking now at FIGS. 4, 6 and 7 , circumferentially-extending side wall125 extends circumferentially about base plate 110 and extends distallyfrom top surface 120 of base plate 110, whereby to define a recess 200extending about drill bit 130 and centered on longitudinal axis 175,which recess 200 is bounded by an inner surface 205 ofcircumferentially-extending side wall 125. Circumferentially-extendingside wall 125 terminates distally in a circumferentially-extendingdistal cutting surface 210 having a plurality of cutting teeth 215formed thereon which are configured to cut into the material which is tobe drilled, as will hereinafter be discussed in further detail. Cuttingteeth 215 are preferably spaced and angled so as to maximize cutting, ina manner that will be apparent to one of ordinary skill in the art inview of the present disclosure.

A cutting wedge 220 (FIG. 6 ) is mounted to, or formed integral with,inner surface 205 of circumferentially-extending side wall 125. Cuttingwedge 220 preferably comprises a sharpened laterally-extending cuttingedge 225 and a sharpened distal cutting edge 230. Cutting wedge 220 (andlaterally-extending cutting edge 225) extends along some or all of innersurface 205 of circumferentially-extending side wall 125 proximally fromdistal cutting surface 210 of circumferentially-extending side wall 125towards upper surface 120 of base plate 110. It should be appreciatedthat cutting wedge 220 may extend all of the distance between distalcutting surface 210 of circumferentially-extending side wall 125 andupper surface 120 of base plate 110, or cutting wedge 220 may extendonly a portion of the distance between distal cutting surface 210 ofcircumferentially-extending side wall 125 and upper surface 120 of baseplate 110. In one preferred form of the invention, cutting wedge 220extends approximately one-half of the distance between upper surface 120of base plate 110 and distal cutting surface 210 (see FIGS. 4, 6 and8-11 ). In another form of the invention, cutting wedge 220 extendssubstantially the entire distance between upper surface 120 of baseplate 110 and distal cutting surface 210 (FIG. 12 ).

It should also be appreciated that, if desired, cutting wedge 220 may beangled relative to longitudinal axis 175 (e.g., cutting wedge 220 may bedisposed at an angle of 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, etc.relative to longitudinal axis 175) such that distal cutting edge 230 ofcutting wedge 220 is disposed forward of the proximal end of cuttingwedge 220 (e.g., in the manner shown in FIGS. 4 and 8 ) whencircumferentially-extending side wall 125 is rotated (e.g.,counter-clockwise from the frame of reference of FIGS. 4 and 8 ). By wayof example but not limitation, distal cutting edge 230 of cutting wedge220 may be disposed forward of the proximal end of cutting wedge 220such that when side wall 125 is rotated (e.g., in a counter-clockwisedirection in the embodiment shown in FIGS. 4 and 8 ), sharpened distalcutting edge 230 enters the material which is to be drilled out at anangle, thereby increasing cutting efficiency, as will be apparent to oneof ordinary skill in the art in view of the present disclosure.

And it should also be appreciated that laterally-extending cutting edge225 (and/or distal cutting edge 230) may be angled relative to the planedefined by inner surface 205 of circumferentially-extending side wall125 so as to enhance cutting. By way of example but not limitation,cutting edge 225 may be disposed substantially perpendicular relative toinner surface 205 of circumferentially-extending side wall 125, cuttingedge 225 may be disposed at an acute angle relative to inner surface 205of circumferentially-extending side wall 125, cutting edge 225 may bedisposed at an obtuse angle relative to inner surface 205 ofcircumferentially-extending side wall 125, etc.

In one preferred form of the invention, and looking now at FIGS. 8-10 ,when drill bit 130 is mounted to base plate 110, drill bit 130 ispreferably rotationally disposed such that the plane defined by flat 190is disposed generally perpendicular to the plane defined by sharpenedlateral cutting edge 225 of cutting wedge 220.

Additionally and/or alternatively, if desired, a portion of distalcutting surface 210 of circumferentially-extending side wall 125 may berecessed so as to provide fingerholds 235 (see FIG. 9 ) for grasping aplug P of drilled out material that is disposed in recess 200 aftercutting is completed, as will hereinafter be discussed in furtherdetail. Where fingerholds 235 are provided, fingerholds 235 arepreferably disposed diametrically-opposed from one another along topsurface 210 of circumferentially-extending side wall 125.

In another embodiment of the present invention, and looking now at FIG.13 , cutting wedge 220 may be omitted. In this form of the invention, aportion of distal cutting surface 210 is deformed laterally inwardly(i.e., towards longitudinal axis 175) such that distal cutting surface210 comprises a non-circular geometry, whereby to provide a cuttingeffect similar to the cutting effect of cutting wedge 220.

Use of Drilling Apparatus to Form a Hole in a Material

In use, novel drilling apparatus 105 is mounted to a drill/motor (notshown) by mounting proximal end portion 160 of drill bit 130 (which is,in turn mounted to base plate 110) to the drill/motor.

Distal point 180 of drill bit 130 is aligned with the center point of animaginary circle inscribed in the material that is to be drilled out,and distal point 180 is advanced distally into the material by rotatingdrill bit 130 (and hence, drilling apparatus 105) using the drill/motorwhile applying a distally-directed force to drill bit 130 (i.e., inorder to cause distal point 180 to engage and enter into the materialthat is being drilled, whereby to center drilling apparatus 105 on thematerial which is to be drilled).

Once distal end portion 165 of drill bit 130 has been advanced into thematerial that is to be drilled, the end user continues to apply adistally-directed force to drilling apparatus 105 while continuingrotation of drilling apparatus 105 (i.e., using the drill/motor). Asintermediate portion 170 of drill bit 130 is advanced distally into thematerial that is to be drilled out, the drill hole formed by distalportion 165 of drill bit 130 is enlarged (i.e., due to thelaterally-extending cutting edge 195 of flat 190 of intermediate portion170 rotating about longitudinal axis 175).

Once drilling apparatus 105 is advanced distally a sufficient distancesuch that cutting teeth 215 disposed on top surface 210 ofcircumferentially-extending side wall 125 engage the material into whicha hole is to be drilled out, the rotation of cutting teeth 215 (i.e.,rotation about longitudinal axis 175) forms acircumferentially-extending groove in the material into which a hole isto be drilled out. Simultaneously, cutting wedge 220 engages thematerial into which a hole is to be drilled out, whereby to laterallyenlarge the circumferentially-extending groove in the material intowhich a hole is to be drilled, but only in the inwardly-directed lateraldirection (i.e., in the direction towards longitudinal axis 175, awayfrom inner surface 205 of circumferentially-extending side wall 125). Asa result, the maximum diameter of the hole drilled in the material isthe same diameter as the diameter of the circle inscribed bycircumferentially-extending side wall 125. However, the diameter of theplug P of material that is drilled out of the hole is smaller than thediameter of the circle inscribed by the plane of inner surface 205 ofcircumferentially-extending side wall 125 (i.e., smaller by thelaterally-extending width of cutting wedge 220), resulting in a plug Phaving a diameter somewhat smaller than the maximum diameter of the holewhich is drilled out of the material.

Similarly, because laterally-extending flat 190 of intermediate portion170 of drill bit 130 extends laterally outboard of longitudinal axis 175of drill bit 130, as laterally-extending flat 190 is rotated aboutlongitudinal axis 175, a central drill hole PH is formed in plug P whichhas a diameter slightly larger than the maximum lateral dimension ofdrill bit 130 (i.e., larger than the maximum width oflaterally-extending flat 190).

Once drilling has been completed (e.g., after drilling apparatus 105 hasbeen advanced all the way through the material in which a hole is to beformed), a plug P of material which is drilled out is disposed in recess200 of drilling apparatus 105 which plug P: (i) has an overall diameterslightly less than the diameter of the circle inscribed by the plane ofinner surface 205 of circumferentially-extending side wall 125, and (ii)has a central drill PH hole having a diameter which is slightly largerthan the maximum lateral dimension of drill bit 130.

As a result of the foregoing, plug P does not bind to eithercircumferentially-extending side wall 125 or drill bit 130 of drillingapparatus 105, and plug P can be easily and quickly removed from recess200 (e.g., by grasping plug P with fingers disposed in fingerholds 235,by tipping drilling apparatus 105 over and allowing plug P to fall outdue to gravity, etc.) without requiring significant effort by the enduser.

Significantly, in addition to the foregoing, it has also been found thatdrilling apparatus 105 facilitates much faster drilling into a materialthan prior art “barrel-style” drill bits. Specifically, as cutting wedge220 is rotated and begins to cut into the material that is to be drilledout, the removal of material by cutting wedge 220 allows cutting teeth215 to more efficiently cut into the material that is being drilled(e.g., by directing debris away from the area where cutting into thematerial is being performed, so that the debris moves towards base plate110). Thus, the present invention not only provides the substantialbenefit of facilitating quick and easy removal of a plug P from recess200, the present invention also provides the unexpected benefit ofincreasing the speed and efficiency of drilling a hole in a material.

MODIFICATIONS

It should be understood that many additional changes in the details,materials, steps and arrangements of parts, which have been hereindescribed and illustrated in order to explain the nature of the presentinvention, may be made by those skilled in the art while still remainingwithin the principles and scope of the invention.

1.-20. (canceled)
 21. A method for drilling out a plug of material, saidmethod comprising: providing apparatus comprising: a base plate having atop surface, a bottom surface, and a central longitudinal axis; acircumferentially-extending side wall extending distally from said topsurface of said base plate, said circumferentially-extending side wallterminating in a circular distal end surface; a drill bit centered onsaid central longitudinal axis of said base plate and extending distallytherefrom, said drill bit comprising a distal portion, a proximalportion and an intermediate portion extending between said distalportion and said proximal portion; wherein said intermediate portion ofsaid drill bit comprises a first laterally-extending flat comprising acutting edge disposed a first distance away from said centrallongitudinal axis towards said circumferentially-extending side wall anda second laterally-extending flat extending a second distance away fromsaid central longitudinal axis towards said circumferentially-extendingside wall, and further wherein said first distance is greater than saidsecond distance; contacting the material with said drill bit; rotatingsaid drill bit such that said drill bit and saidcircumferentially-extending side wall engage with, advance into, andpass through, the material such that a plug of the material is cut outof the material.
 22. The method according to claim 21 wherein saidcutting edge of said first laterally-extending flat is sharpened tofacilitate cutting into the material.
 23. The method according to claim21 wherein said drill bit is releasably mounted to said base plate, andfurther wherein rotation of said drill bit effects simultaneous rotationof said base plate.
 24. The method according to claim 23 wherein saiddrill bit further comprises a drill bit mounting plate mounted to saidproximal portion of said drill bit, and further wherein said drill bitmounting plate comprises a plurality of tabs configured to be receivedin a plurality of openings formed in said base plate.
 25. The methodaccording to claim 21 wherein said distal portion of said drill bitcomprises a tapered point centered on said longitudinal axis, andfurther wherein said tapered point comprises a spiral recess extendingfrom a distal end of said distal portion of said drill bit to a proximalend of said distal portion of said drill bit.
 26. The method accordingto claim 21 wherein at least one of said first laterally-extending flatand said second laterally-extending flat comprises a non-planar geometryalong the length of said intermediate portion of said drill bit.
 27. Themethod according to claim 26 wherein at least one of said flatlaterally-extending flat and said second laterally-extending flatcomprises a spiral geometry along the length of said intermediateportion of said drill bit.
 28. The method according to claim 21 whereina distal end of said distal portion of said drill bit extends distallybeyond a plane extending parallel to said top surface of saidcircumferentially-extending side wall.
 29. The method according to claim21 wherein said circumferentially-extending side wall comprises an innersurface and an outer surface, and further wherein a cutting wedge ismounted to said inner surface of said circumferentially-extending sidewall and extends laterally inwardly in the direction of saidlongitudinal axis.
 30. A method for drilling out a plug of material,said method comprising: providing apparatus comprising: a base platehaving a top surface, a bottom surface, and a central longitudinal axis;a circumferentially-extending side wall extending distally from said topsurface of said base plate, said circumferentially-extending side wallcomprising an inner surface defining a circular recess enclosed by saidcircumferentially-extending side wall, an outer surface and a circulardistal end surface; a cutting wedge mounted to said inner surface ofsaid circumferentially-extending side wall and extending laterallyinwardly in the direction of said longitudinal axis; contacting thematerial with said circumferentially-extending side wall; rotating saidcircumferentially-extending side wall such that saidcircumferentially-extending side wall and said cutting wedge engage,advance into, and pass through, the material such that a plug of thematerial is cut out of the material.
 31. The method according to claim30 wherein said cutting wedge comprises a sharpened lateral edge alongthe portion of said cutting wedge extending away from said inner surfaceof said circumferentially-extending side wall.
 32. The method accordingto claim 30 wherein said cutting wedge comprises a sharpened distal end.33. The method according to claim 30 wherein said cutting wedge extendshalf of the distance between (i) a plane disposed parallel to saidcircular distal end surface of said circumferentially-extending sidewall, and (ii) the top surface of said baseplate.
 34. The methodaccording to claim 30 wherein said cutting wedge is mounted to saidinner surface of said circumferentially-extending side wall at an anglerelative to said longitudinal axis.
 35. The method according to claim 30further comprising a drill bit extending distally from the top surfaceof said baseplate, and further wherein said drill bit is centered onsaid longitudinal axis.
 36. The method according to claim 35 whereinsaid drill bit comprises a distal portion, a proximal portion and anintermediate portion extending between said distal portion and saidproximal portion; and wherein said intermediate portion of said drillbit comprises a first laterally-extending flat comprising a cutting edgedisposed a first distance away from said central longitudinal axistowards said circumferentially-extending side wall and a secondlongitudinally-extending flat extending a second distance away from saidcentral longitudinal axis towards said circumferentially-extending sidewall, and further wherein said first distance greater than said seconddistance.
 37. The method according to claim 36 wherein said cutting edgeof said first laterally-extending flat is sharpened to facilitatecutting into a material.
 38. The method according to claim 36 wherein atleast one of said first laterally-extending flat and said secondlaterally-extending flat comprises a non-planar geometry along thelength of said intermediate portion of said drill bit.
 39. The methodaccording to claim 38 wherein a distal end of said distal portion ofsaid drill bit extends distally beyond a plane extending parallel tosaid top surface of said circumferentially-extending side wall.
 40. Amethod for drilling out a plug of material, said method comprising:providing apparatus comprising: a base plate having a top surface, abottom surface, and a central longitudinal axis; acircumferentially-extending side wall extending distally from said topsurface of said base plate, said circumferentially-extending side wallcomprising an inner surface defining a circular recess enclosed by saidcircumferentially-extending side wall, an outer surface and a circulardistal end surface; a drill bit centered on said central longitudinalaxis of said base plate and extending distally therefrom, said drill bitcomprising: a distal portion; a proximal portion; and an intermediateportion extending between said distal portion and said proximal portion;wherein said intermediate portion of said drill bit comprises a firstlaterally-extending flat comprising a cutting edge disposed a firstdistance away from said central longitudinal axis towards saidcircumferentially-extending side wall and a second laterally-extendingflat extending a second distance away from said central longitudinalaxis towards said circumferentially-extending side wall, and furtherwherein said first distance is greater than said second distance; and acutting wedge mounted to said inner surface of saidcircumferentially-extending side wall and extending laterally inwardlyin the direction of said longitudinal axis. contacting the material withsaid drill bit; rotating said drill bit such that said drill bit andsaid circumferentially-extending side wall engage with, advance into,and pass through, the material such that a plug of the material is cutout of the material.